Aggregate throughput in multi-hop ad-hoc networks suffers from the
presence of hidden and exposed nodes. While there are various
approaches to mitigating these problems, in this work we focus
exclusively on the role of physical carrier sensing (PCS).
Specifically, tuning the PCS threshold impacts the `exposed' and
`hidden' areas differently; increasing one typically decreases the
other, indicating a trade-off. In this work, we first develop an
analytical model (assuming constant rate nodes) and formulate an
optimization problem to determine the optimal PCS threshold. It is
shown that under some conditions, the carrier sensing range should
be chosen to equal the interference range. Numerical results with
MATLAB and simulations with OPNET are used to verify the optimality
of this result. Finally, we extend the analytical model to more
general scenarios - random networks with multi-rate - for optimizing
aggregate throughput.